Comet C/2023 A3 (Tsuchinshan-ATLAS) |
Click on photo for larger image. |
Comets are balls of ice, rocks, frozen carbon dioxide, carbon monoxide, ammonia, and methane. They are thought to mostly reside in a region called the Oort cloud, a distant collection of small objects orbiting the sun 2,000 to 200,000 times farther from the sun than is the earth. A gravitational perturbation occasionally knocks one of these objects into an orbit that enters the inner solar system. Such an event produced comet C/2023 A3 (Tsuchinshan-ATLAS), photographed here shortly after it passed by the sun in September 2024. |
Radiation from the sun vaporizes some of the comet and the solar wind blows the debris outward, producing the characteristic tail. Just visible in this photo is also the "anti-tail" formed by heavier particles knocked loose from the comet that orbit behind its path. |
The comet is named for the year of its discovery and the two observatories that first identified it. The Tsuchinshan (Purple Mountain) Observatory is in China. ATLAS (Asteroid Terrestrial-impact Last Alert System) is a network of observatories; the site in South Africa shared in the discovery. |
Whether this comet is in a periodic orbit or is on a path leading to ejection from the solar system is not currently known. |
The field-of-view in this photograph is 9.4 x 6.4 degrees. For comparison, the angular size of the moon in the sky is 0.5 degrees. A video showing a close-up view of the motion of the comet's head is here. |
Craig Lent, 31 minutes, ZWO ASI2600 pro, Rokinon 135mm FL lens @ f/2.0 |